Aluminum phosphate compositions, coatings and related composites and applications

ABSTRACT

Composites comprising an aluminum phosphate-based coating component and methods for sealing porous substrate surfaces.

This application is a continuation of and claims priority benefit frompending application Ser. No. 11/244,539 filed Oct. 5, 2005, now U.S.Pat. No. 8,021,758 which is a continuation in part of and claimspriority from pending application Ser. No. 10/745,955 filed on Dec. 23,2003, now U.S. Pat. No. 7,311,944, which claimed priority fromapplication Ser. Nos. 60/615,920 and 60/615,986, filed contemporaneouslyon Oct. 5, 2004, each of which is also incorporated herein by referencein its entirety.

FIELD OF INVENTION

This invention can relate to aluminum phosphate coatings deposited onsubstrates, for imparting desirable electrical, chemical, mechanical,and physical properties. The invention can also teach methods to sealporous materials and also teaches new compositions and modifications ofaluminum phosphate materials.

BACKGROUND OF THE INVENTION

There are a number of prior art patents related to synthesis of aluminumphosphate materials primarily for use as a catalyst support includingcrystalline and amorphous forms. Most synthetic methods comprise ofusing a sol-gel technique with raw materials that include commonlyavailable salts of aluminum and a variety of phosphorous sourcesincluding phosphoric acid, ammonium hydrogen phosphates, phosphorousacid, and others. Many of these methods yield crystalline forms and fewthermally stable amorphous compositions (U.S. Pat. Nos. 4,289,863, Hilland al.; 5,698,758, Rieser and al.; 6,022,513, Pecaro and al.). Theprior art materials, for example, cannot be used as a coating forprotecting substrates from corrosion or oxidation at elevatedtemperatures.

It is desirable to use an amorphous dense coating that is thermallydurable and stable to protect various substrates in industrial andconsumer use applications. The prior art coatings are either not durableunder certain atmospheric conditions or under certain harsh industrialor use environments where materials are subjected to thermal treatmentsor exposed to corrosive environments. Silica-based amorphous coatingshave been developed and a recent patent prescribes a unique way todeposit such coatings (U.S. Pat. No. 6,162,498). However, the coating isnot durable under certain harsh conditions and is not thermally stableat elevated temperatures or do not serve adequately as a transparentcoating on glass. High temperature stable glassy or vitreous coatingshave also been developed by initially coating substrates with a slurryof glass frits and subsequently treating the coated material to highenough temperatures to melt the glass frits and form the vitreouscoating. Vitreous enamel coatings have been in existence for manydecades with many different compositions. However, they are usuallythick and deform at elevated temperatures. The requirement of hightemperature processing to melt the glass frits may degrade the substrateand if low melting glass compositions are selected, they may not bedurable.

Vapor deposited inorganic coatings are currently under use for manyapplications, however, they require expensive equipment and are notsuitable for non-line of sight substrate geometries (For example, U.S.Pat. No. 3,442,686, U.S. Pat. No. 4,702,963, U.S. Pat. No. 5,434,008,U.S. Pat. No. 5,792,550). Solution-derived inorganic coatings providelow-cost and conformal ability to coat substrates.

Some of the prior art inorganic coatings are also not completelytransparent for use on glass where transmission properties are affectedor other substrates where aesthetic property of the substrate (metallicappearance) needs to be preserved.

Brushed steel and other related solid surfaces are used extensively infacades in buildings, malls, elevators, table lamps, bath fixtures,cabinet doors, wall plates and others. Desirable properties of thesesurfaces include easy-to-clean and finger print resistance along withadequate durability under exposure from thermal load or heat, sun-light,various solvents and common cleaning agents, UV-radiation, and providenon-stick against foods and other related properties.

Porous surfaces are susceptible to contamination when used for storageand like purposes. Enamel, granite, marble, floor tiles, glass,porcelanized stoneware, oven and related cooking appliances in akitchen, oven interior panels, food trays, cooktops and other ceramicsurfaces possess micro as well as macro pores and defects which are notdesirable in their end application. Sealing of pores on granite, forexample on kitchen countertops, will help impart anti-stainingproperties. Hermetic sealing of these pores will also help reduce gaspermeation which is important in certain applications. Polymer surfacetreatments are well known in the art to seal ceramic surfaces, however,their durability is limited under heat, exposure to cleaning solvents oragents, and are relatively soft. A suitable thin inorganic coating whichis chemically inert and thermally stable is desired. Many of theseapplications represent high volume sales such that low cost coatingtechniques are important for consideration with solution-based dip orspray coating being the most preferred method of application. Suchtreatments can also enable self-cleaning surfaces, easy-to-clean,biosafety, aesthetic value, hardness and abrasion resistance,antimicrobial combined with solvent resistance. Also, such a sealantshould have good thermal shock properties (for example, hot pan ongranite table) and thermal stability; even if the sealant is worn off,the effect of filling pores on the surface would help extend thedurability of the coating significantly. Inventive material on anodizedaluminum parts and other related materials can provide improvements toperformance and durability along with environmental and energy savings.The inventive material can be used as a hermetic sealing of ceramics andadhesion promoter (monolithic, composites, and glass-ceramic) in variousapplications including tile, substrates for electronic packaging andrefractories to improve durability and lower gas permeability.

Silicon carbide has excellent properties for space-based and airborneplatform optical materials, but the brittle nature along with the highhardness of the material makes it difficult to finish to tolerancesrequired. Polishing the surface to a fraction of the wavelength of lightto be reflected takes weeks to months, depending on size and shape ofthe substrate.

Current low dielectric materials do not have the required dielectricconstant values in combination with thermal and mechanical stability.New low k materials are required to improve the present state ofsemiconductor field.

Researchers are working to combine polymer and metal-foil substrateswith printable TFT backplanes to move flexible displays closer tocommercial reality. For years, the “holy grail” of the displayindustry—as of yet, largely unobtainable—has been a thin, clear,flexible substrate with barrier properties equal to those of a sheet ofglass. Again, the prior art has been somewhat deficient in this regard.

Photomasks are high precision plates containing microimages ofelectronic circuits. Architecture should be maintained to achieve defectfree photomasks. Problems arise when the chrome layer is affected byenvironments or interlayer reactions. There are cosmetic defectsincluding scratches on the chrome outside the array, damaged orpartially removed AR coating, contamination on the chrome, glass chipson the edge of the mask, etc.—all of which need to be avoided. Coatingsshould be very thin, in the range of approximately 10 nanometers, anddefect free.

Plastic materials, in general, are susceptible to degradation fromabrasion, moisture attack, UV radiation, atomic oxygen, exposure tosolvents, chemicals and many others. Vapor deposited inorganic coatingson plastics are currently under use for many applications, however, theyrequire expensive equipment and are not suitable for non-line of sightsubstrate geometries (For example, U.S. Pat. No. 3,442,686, U.S. Pat.No. 4,702,963, U.S. Pat. No. 5,434,008, U.S. Pat. No. 5,792,550).Therefore, there is a need for low-cost solution-derived protectivecoatings (inorganic and inorganic-organic composite) for plasticsubstrates with suitable processing schemes to develop reel-to-reel orroll-to-roll continuous processing as well as the ability to coatcomplex-shaped substrates.

Unlike glass and metal, however, all polymers exhibit a measurabledegree of permeability to gases and vapors. Numerous technologies havebeen developed to decrease the permeability of polymers, and thusincrease their range of applicability to food and beverage packaging. Apermeation barrier layer is also important whenever a permeant materialhas to be transported. Tubes and hoses for gasoline, fluorocarbonvapors, etc. (important in automotive and appliance applications),require barrier performance beyond that currently available. Likewise,thin defect and pinhole-free inorganic moisture and oxygen barriercoatings are need for these display applications.

SUMMARY OF INVENTION

In light of the foregoing, it is an object of the present invention toprovide aluminum phosphate-based compounds, compositions, coatingsand/or related composites or articles, together with methods for theiruse and preparation, thereby overcoming various deficiencies andshortcomings of the prior art, including those outlined above. It willbe understood by those skilled in the art that one or more aspects ofthis invention can meet certain objectives, while one or more otheraspects can meet certain other objectives. Each objective may not applyequally, in all its respects, to every aspect of this invention. Assuch, the following objects can be viewed in the alternative withrespect to any one aspect of this invention.

For purposes of the present invention, the phrase “inventive material,”mention thereof or reference thereto will be understood to mean any ofthe present aluminophosphate-based compounds or compositions, over theentire available range of Al:P stoichiometries, as may be used inconjunction with a method, composite, or article of this invention,and/or a film, layer or coating associated therewith, or as otherwiseprovided below, such compounds or compositions prepared or characterizedas described herein, such compounds and compositions as may bealternatively expressed, respectively, as aluminum phosphate compoundsand compositions, and prepared, characterized and/or applied asdescribed in any of the aforementioned incorporated references and/or inU.S. Pat. Nos. 6,036,762 and 6,461,415 and co-pending application Ser.Nos. 10/362,869 filed Jul. 15, 2003, and 10/627,194 and PCT/US03/36976,filed Jul. 24, 2003 and Nov. 19, 2003, respectively, and 10/642,069 andPCT/US03/25542 filed Aug. 14, 2003, each of which is incorporated hereinby reference in its entirety. Without limitation, as described hereinand/or through one or more of the aforementioned incorporated patents orapplications, the inventive material can include such aluminumphosphate-based compounds and compositions comprising dopants, particlesand/or inclusions of organic molecules, polymers, carbon, silicon,metals, metal oxides and/or other metal ions/salts—includingnonoxides—regardless of whether the aluminum content is stoichiometric,less than stoichiometric or greater than stoichiometric relative tophosphorous, on a molar basis. Embodiments of the inventive materialsare available under the Cerablak trademark from Applied Thin Films, Inc.

The “inventive material” also comprises aluminum phosphate-basedmaterials and can be deposited as a thin film on substrates using aspecially-designed precursor solution that yields a unique form ofamorphous aluminum phosphate. U.S. Pat. Nos. 6,036,762 and 6,461,415issued to Sambasivan et. al and the above-referenced patent applicationsprovide details regarding the precursor synthesis and chemistry,properties, and other processing details are provided. Various additionsor modifications to surfaces coated with the inventive material are alsoconsidered embodiments of the present invention, examples of which areprovided below.

Likewise, the term “substrate” or phrase “solid substrate” includes anysolid materials including but not limited to polymers, plastics,ceramics, metals, alloys, silicon carbide, silicon, oxides,chalcogenides, pnictides, quartz, glass, and others.

One or more of the following objects can be achieved in conjunction withan inventive material coating on a variety of substrates, withparticular emphasis on roll-to-roll continuous coating of substrates toprovide substrate protection against various environmental factorsincluding, moisture, oxygen UV light, and others. Accordingly, suchinventive material coatings can act as protective as well as functionalcoatings.

It is an object of the invention to use inventive material coatings asan insulating layer with effective dielectric strengths for use invarious applications requiring electrical isolation such as aphotovoltaic device on a conductive substrate.

Another object of the invention is to provide a coating or film of theabove character which can maintain given moisture content within apackaged volume.

It is an object of this invention to use the inventive material asanti-iridescent and anti-tarnishing coatings.

The invention pertains to an improved method of forming inventivematerial layer on a metal surface, to provide an interface for promotingadhesion between the metal surface and an organic polymer coating, andto the resulting oxide layer coated metal surface. The method involvesapplying, to a metal surface, the inventive material. The resultingcoating layer can serve as an interface for promoting adhesion betweenthe metal surface and an organic polymer coating.

An object of invention is also to use inventive material coating inhousings for moisture sensitive devices, such as moisture sensitiveoptical devices, which comprise a plurality of metal plates soldered attheir edges to define the housing, wherein an organic polymer coating isapplied to at least the exterior surfaces of the housing at the jointsto provide a moisture barrier which prevents corrosion at the joints.

One of the objects of the invention is to provide a method to depositthis inventive material coating as a thin, hermetic, microstructurallydense, uniform, and transparent coating using simple dip, spin, spray,brush or flow coating process.

It is an object of the invention is to use inventive material coatingsto protect solid substrates from moisture, light, gases, chemicals andother environmental effects.

It is also an object of the invention to protect surfaces of solidsubstrates during processing and service at room and elevatedtemperatures.

It is also an object of the invention to improve the mechanicalproperties of solid substrates including but not limited to scratchresistance, stain resistance, abrasion resistance, erosion resistance,damage occurring from the impact of high velocity particles, rain,water, liquids and other objects.

It is also an object of this invention to protect space solid materialsfrom low earth orbit environment such as high flux of atoms andmolecules such as oxygen, hydrogen, nitrogen and like.

It is an object of this invention to use inventive material as primer oradhesion promoting layer on polymeric surfaces.

It is an object of this invention to use inventive material as primer oradhesion promoting layer on metallic surfaces.

It is an object of this invention to use inventive material as primer oradhesion promoting layer on ceramic surfaces.

It is an object of this invention to use inventive material as primer oradhesion promoting layer on metal chalcogenides surfaces.

It is an object of this invention to use inventive material as primer oradhesion promoting layer on solid substrate surfaces.

It is an object of this invention to use inventive material as anadhesive or bonding two of similar of different types of materials.

It is an object of this invention to use inventive material as anadhesive or bonding of two similar different optical materials.

It is an object of this invention to use the inventive material to coverthe surface defects and seal of pores on solid substrate surfaces.

It is an object of this invention to planarize the coated solidsubstrates surfaces.

It is an object of this invention to reduce the friction on coated solidsubstrates surfaces.

It is an object of invention to use inventive material as an antistaticcoating on solid substrates.

It is an object of the invention to use inventive material coatings as alow-dielectric layer on solid substrates.

It is an object of the present invention to use inventive material andmodified inventive material coatings as antireflective layer on polymerand like substrates.

It is an object of the invention to use inventive material coatings asmoisture and oxygen barrier in flexible displays architecture.

It is an object of the invention to use inventive material coatings asbarrier against mechanical damage of solid substrates.

It is an object of the invention to use inventive material coatings fortailoring optical property of solid materials.

It is an object of the invention use inventive material coatings toprotect polymers, thermoplastics and like materials againstphoto-degradation.

It is an object of the invention to use inventive material coatings toprotect solid substrates against damaging microbials.

It is an object of the invention to use inventive material coatings onmedical instruments and parts made of solid materials from chemical andphysical damage.

It is an object of the invention to use inventive material coatings onmedical instruments and parts made of solid materials from body fluidscorrosion.

It is an object of the invention to use inventive material coatings andmodified inventive materials on medical instruments and devices,implants and other parts to impart biocompatibility.

It is an object of the invention to use develop biocompatible materialsincorporated inventive material and inventive material coatings on solidsubstrates.

It is an object of the present invention to provide a barrier filmhaving high colorless transparency and a method for making the same.

Another object of the invention is to provide a film of the abovecharacter which has a thickness in the range of about 10- about 500 nm.

Another object of the invention is to provide a coating or film of theabove characters which has low friction.

Another object of the invention is to provide a coating or film of theabove characters which can be produced at a reduced cost.

Another object of the invention is to provide a coating or film of theabove characters which reduces the total volume of solid materialsrequired in devices.

Another object of the invention is to provide a coating or film of theabove character which reduces the difficulty of recycling.

Another object of the invention is to provide a coating or film of theabove character which can be utilized for food packaging which can beused in microwave ovens.

Another object of the invention is to provide a coating or film of theabove character which can be utilized for packaging food which can beused in a microwave unit and still be transparent with a long shelflife.

Another object of the invention is to provide a coating or film of theabove character which can maintain given moisture content for contentspackaged in the barrier film.

Another object of the invention is to provide a coating or film andmethod in which the barrier film can be produced at high productionspeeds.

Another object of the invention is to provide a coating which canplanarize the polymer surface and can help in reducing the scattering oflight.

It is also an object of the present invention to provide a functionalcoating preferably an electrically conducting or magnetic coating onsolid substrates through the dispersion of additives in inventivematerial precursor solution.

It is also an object of the present invention to provide an improvedaircraft transparency; by using inventive material coating on solidsubstrate and an electroconductive metal oxide coating disposed over thesolid substrate.

It is also an object of the present invention to provide protective andadhesion promoter layer for aircraft transparency.

It is also an object of the present invention to develop inventivematerial mixed with inorganic polymers and molecules such as P and Bcontaining material such as phosphazene, borazine or borozole.

It is also an object of the present invention to develop inventivematerial and inventive material coating dispersed with boron nitride,molebdenum silicide, molybdenum sulfide or other lubricant materials inorder to form high temperature lubricant coatings.

It is also an object of the present invention to develop inventivematerial with low-dielectric constant by suitably modifying themicrostructure of the inventive material, in particular increase theporosity of the inventive material coating.

This invention is directed toward the use of inorganic andinorganic-organic composite coatings based on aluminum phosphatecompositions on plastic or polymeric substrates for improved protectionagainst abrasion or wear and from environmental attack.

In particular, this invention relates to the precursor solutionchemistry or curable coating composition utilized to derive thestructure and nature of the protective coating deposited on plastic orpolymeric substrates.

An object of the invention was to tailor the precursor chemistrycontaining Al, P, and O, and other species to form a coating with goodadhesion and substantially inorganic coating under relatively lowtemperature curing conditions.

A further object of the invention is to include trapped water orhydroxyls, organics and presence of some nitrate or other salts in thesubstantially-inorganic coating to promote flexibility and toughness ofcoatings.

A further object of the invention, in general, is to add certain organicand inorganic additives to the curable coating composition containingaluminum phosphate compounds to favorably tailor the curing conditionsfor minimizing stresses and add other functionalities to the coatings.

A further object of the invention is to use multilayers comprising of anadhesion promoting underlayer, such a layer being substantiallyinorganic or an inorganic-organic hybrid in nature and overlayers thata) seal microcracks of the underlying layer that improve barrierproperties, such layers being substantially inorganic or aninorganic-organic hybrid in nature, and b) comprise of certain organicor inorganic additives to improve solvent resistance or abrasion of thecoating system, such that the total thickness of the multilayer systemdo not exceed about 15 microns, more preferably about 10 microns, andmost preferably about 5 microns.

A further object of the invention is to develop stable sprayableformulations that are curable upon thermal or UV or IR radiation ormicrowave treatments. Curing can be effected with one or combination ofmore than one treatment methods.

A further object of the invention is to develop aluminum phosphate-basedcoatings that are substantially transparent to visible spectrum of theelectromagnetic radiation.

A further object of the invention is to either deposit a top organiclayer or to incorporate specific organic additives into the curableformulation to promote durable hydrophobic or hydrophilic properties.

A further object of the invention is to utilize the aluminum phosphatebased coating composition as an adhesive to bond the plastic substratesto other metal, ceramic, glass, and other plastic materials.

One of the objects of the invention is to provide a method to depositthis inventive material coating as a thin, hermetic, microstructurallydense, uniform, and transparent coating using simple dip, spin, spray,brush or flow coating process.

It is an object of the invention is to use inventive material coatingsto protect plastics, polymers and like materials from moisture, light,gases and other environmental effects.

It is an object of the invention is to use inventive material as barrierfilm against inert gases (e.g. oxygen, nitrogen, hydrogen), tochemically active gases (e.g. water, carbon dioxide), and to liquids andvapors (e.g. aromas, fine chemicals, gasoline).

It is also an object of the invention to protect surfaces of polymersduring processing and service at room and elevated temperatures.

It is also an object of the invention to improve the mechanicalproperties including but not limited to scratch resistance, abrasionresistance, damage occurring from the impact of high velocity particlesand other objects.

It is also an object of this invention to protect space polymers fromlow earth orbit environment such as high flux of atoms and moleculessuch as oxygen, hydrogen, nitrogen and like.

It is an object of this invention to use inventive material as primer oradhesion promoting layer on polymeric surfaces.

It is an object of this invention to use the inventive material to coverthe surface defects and seal of pores on polymer surfaces.

It is an object of this invention to planarize the coated polymersurface.

It is an object of this invention to reduce the friction on coatedpolymer surface.

It is an object of invention to use inventive material as an antistaticcoating on polymers and related substrates.

It is an object of the invention to use inventive material coatings as adielectric layer.

It is an object of the present invention to use inventive material andmodified inventive material coatings as antireflective layer on polymerand like substrates.

It is an object of the invention to use inventive material coatings asmoisture and oxygen barrier in flexible displays architecture.

It is an object of the invention to use inventive material coatings asbarrier against mechanical damage.

It is an object of the invention to use inventive material coatings fortailoring optical property of polymeric and like materials.

It is an object of the invention use inventive material coatings toprotect polymers, thermoplastics and like materials againstphoto-degradation.

It is an object of the invention to use inventive material coatings toprotect against damaging microbials.

It is an object of the invention to use inventive material coatings onmedical instruments and parts made of polymers and like materials fromchemical and physical damage.

It is an object of the present invention to provide a barrier filmhaving high colorless transparency and a method for making the same.

Another object of the invention is to provide a barrier film of theabove character having high transparency.

Another object of the invention is to provide coating or film of theabove character which has an overall reduced thickness.

Another object of the invention is to provide a film of the abovecharacter which has a thickness in the range of about 10- about 500 nm.

Another object of the invention is to provide a coating or film of theabove character which will not curl the coated polymeric flexiblesubstrate.

Another object of the invention is to provide a coating or film of theabove character which has low friction.

Another object of the invention is to provide a coating or film of theabove character which can be produced at a reduced cost.

Another object of the invention is to provide a coating or film of theabove character which reduces the total volume of plastics or polymersrequired in devices.

Another object of the invention is to provide a coating or film of theabove character which reduces the difficulty of recycling.

Another object of the invention is to provide a coating or film of theabove character which can be utilized for food packaging which can beused in microwave ovens.

Another object of the invention is to provide a coating or film of theabove character which can be utilized for packaging food which can beused in a microwave unit and still be transparent with a long shelflife.

Another object of the invention is to provide a coating or film of theabove character which can maintain given moisture content for contentspackaged in the barrier film.

Another object of the invention is to provide a coating or film andmethod in which the barrier film can be produced at high productionspeeds.

Another object of the invention is to provide a coating which canplanarize the polymer surface and can help in reducing the scattering oflight.

It is another object of the present invention to provide an improvedpolymeric substrate for an electronic or optoelectronic device throughthe inventive material coating, which can avoid or at least reduce theproblems of the prior art.

It is also an object of the present invention to provide a functionalcoating preferably an electrically conducting or magnetic coating onpolymeric substrate through the dispersion of additives in inventivematerial precursor solution.

It is also an object of the present invention to provide an improvedaircraft transparency; by using inventive material coating on plasticsubstrate and an electroconductive metal oxide coating disposed over theplastic substrate.

It is also an object of the present invention to provide protective andadhesion promoter layer for aircraft transparency.

Accordingly, the present invention can relate to the development ofmaterial which can be inorganic, an organic-inorganic composite orpredominately inorganic in composition. In certain embodiments, aluminumphosphate-based materials which can be useful in a number ofapplications where it can be used in powder, bulk, fiber, and as acoating. The present invention can relate to application of aluminumphosphate-based coating on a variety of solid substrates including butnot limited to plastics, polymers, metals, alloys, ceramics, silicon,silicon carbide, quartz, sapphire, glass and other substrate materials.The present invention can also relate to retention of surface propertiessuch as reflectivity of metal or other reflective surfaces through thealuminum phosphate-based material coating under a variety of exposureconditions including but not limited to high temperature treatment, UVradiation, moisture etc. This invention can also relate to applicationof aluminum phosphate-based coatings as barrier coating against thediffusion of gases, water and other fluids on a variety of substrates.This invention can also relate to use of aluminum phosphate-basedprecursor solution as spin-on-glass (SOG) material in systems witharchitecture consisting of narrow gaps and non-uniform surfaces, forexample, semiconductor devices and optical layers. The present inventiongenerally relates to surface treatment or coating of polymer and plasticsolid substrates utilizing aluminum phosphate based materialcompositions. The present invention can also relate to a method ofimproving adhesion between polymer and other types of materials.

In part, the present invention can be directed to a configured compositecomprising a substrate and a coating component thereon. The coatingcomponent can comprise an aluminum phosphate compound comprising analuminum-to-phosphorous ratio that can range from less than about 0.5 toabout 1, to about 10 to about 1, to about 20 to about 1, or,alternatively, to about 25 to about 1. Such a composite can be arrangedabout an axis substantially perpendicular to the configuration provided.

In certain embodiments, the substrate can be configurationally flexible,such that a composite thereof with such a coating component can be woundabout a spool and/or unwound for subsequent fabrication into an articleof manufacture. Accordingly, as would be understood in the art, such asubstrate can be selected from a metal, a metal alloy, and a plastic. Incertain such embodiments, such a metal substrate can be selected fromstainless steel and brushed stainless steel. Regardless, as describedelsewhere herein, a coating component of this invention can besubstantially transparent in the visible spectrum and/or can provide acomposite and iridescent appearance. Alternatively, such a coatingcomponent can comprise one or more additive components or agents toprovide the composite and antimicrobial function, such agents as wouldbe understood by those skilled in the art made aware of this invention.Further function or effect can be derived by interposing one or moreinterlayer components between the substrate and the coating component,such interlayer components, as also described herein.

In certain other embodiments, the substrate can comprise a plasticmaterial comprising one or more of a polycarbonate and/or a copolymerthereof, a polyimide and/or a copolymer thereof, and a polyester and/ora copolymer thereof. Without limitation, other such polymeric materialsare described elsewhere herein, and would be understood by those skilledin the art made aware of this invention. Regardless of substrateidentity, a coating component therewith can provide a permeation barrierwith respect to moisture, gas, and/or another permeant. Alternatively,such a component can provide a protective function, as to a plasticsubstrate, with regard to the deleterious effects of organic solvents.Regardless of functional benefit provided the substrate, an overlayercomponent can be positioned on or above the coating component, forfurther functional benefit of the composite. Depending on the substrateidentity and various compositional aspects of the coating component, asdescribed elsewhere herein, the coating component can be identified ascomprising a structural moiety absorbing radiation in the infraredspectrum at about 1230 cm⁻¹.

In certain other embodiments, a substrate component can comprise a metalfoil. Without limitation, such a substrate can be dimensioned, dependingupon end use application, less than about 100 mils. Such foil substratescan be selected from aluminum, stainless steel, titanium, magnesium,nickel-based alloys and superalloys. As mentioned above, such compositescan further include various interlayer components and overlayercomponents. For instance, without limitation, a metal overlayercomponent on such a coating component can provide a mirror-likereflective surface, benefiting such a composite for use in variouslighting applications.

In part, the present invention can also provide a method of using analuminum phosphate composition to seal a porous substrate surface. Sucha method can comprise: providing a substrate comprising a surfacecomponent; contacting the surface component with a compositioncomprising an aluminum phosphate compound comprising at least onephosphate ester moiety; and heating the composition at a temperature andfor a time sufficient to at least partially remove and/or oxidize one ofthe ester moieties. Without limitation, in such embodiments, thesubstrate can be selected from granite, marble, engineered or processedstone materials, porcelain, and a range of ceramic materials.Regardless, such a method can provide a surface component substantiallyplanarized with a contacted composition substantially thermally-stableup to a temperature of about 100° C.

In certain embodiments, such a composition can be sprayed on the surfacecomponent. Depending upon a particular application or processingrequirement, such a composition can comprise at least one of an aqueouscarrier component, a non-aqueous carrier component, and an aerosolpropellant, such components as would be understood by those skilled inthe art made aware of this invention. As contemplated within the broaderaspects of this invention, such a method, can be used in conjunctionwith various kitchen appliances and counters, bathroom counters andfixtures, and flooring and wall tile components, whether during themanufacture of such articles or as such compositions can be subsequentlyapplied thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a FTIR image of the sample prepared in example 4 showingabsorption peaks corresponding to phosphate and water groups in thecoating.

FIG. 2 is a FTIR image of the sample prepared in example 6 showingabsorption peaks corresponding to phosphate and water groups in thecoating.

FIG. 3. is a cross-sectional TEM image and of inventive material coatingon Sapphire showing hermetic, dense and uniform nature. Electrondiffraction pattern corresponding to inventive material layer showsnon-crystalline nature.

FIG. 4 is a photograph of enamel coupon partially coated with inventivematerial after food-adhesion test.

FIG. 5 is a photograph of uncoated silicon carbide surface with 1 μmpolish (left) and inventive material coated SiC after heat treatment(right), showing reflective surface.

FIG. 6 shows atomic force microscopic (AFM) images of inventive materialcoated, heat treated silicon carbide.

FIG. 7 shows AFM images of inventive material coated, heat treated metalalloy.

FIG. 8 is a photograph of copper plate partially coated with inventivematerial.

FIG. 9 shows AFM images of uncoated Glass (rms ˜1-2 nm) (left) andInventive Material Coated (rms ˜0.1-0.2 nm) (right).

FIG. 10 shows FTIR spectra of inventive material coating on stainless asa function of temperature length of heat treatment at 200° C.

FIG. 11 is a FTIR spectra of flash-cured inventive material coating on astainless steel foil.

FIG. 12 is a SEM micrograph of inventive material coated surface ofpolyimide film.

FIG. 13 is a UV-Vis absorption spectrum of the undoped inventivematerial and zincoxide nanoparticles dispersed inventive materialcoating.

FIG. 14 is a photograph of fused quartz sample partially coated withinventive material showing the barrier effect of coating againstenvironmental attack.

FIG. 15 is a transmission spectra of sapphire/ZnS bonded couple. Thedecreased transmission above 6 μm is due to sapphire.

FIG. 16 is a transmission spectra of inventive material On ZnS.

FIG. 17 and FIG. 18 schematically illustrate roll-to-roll processing andresulting composite configurations in accordance with this invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Enamel surfaces used in kitchen appliances such as oven etc. arechemically complex with various alkalis mixed with alumino-borosilicateand are susceptible to chemical reactions with various food chemicals.The reaction products adhere strongly to the surface and cannot beeasily removed requiring strong cleaning solutions (caustic treatments)which are toxic in nature. In addition, the surfaces have some level ofporosity that cause mechanical interlocking of particles which are alsodifficult to remove. No surface treatment solution has been attempteddue to the lack of a low-cost solution that affords a sealing effectwith stable, inert, and low surface energy. The use of inventivematerial films as a seal coat represents the key innovation for thisapplication.

For oven cavity applications, a inventive material coating is needed toreduce the surface porosity by at least 50%, to keep the burnt-on foodfrom becoming mechanically interlocked with the enamel surface, makingcleaning difficult. In addition, lowering the surface energy of theenamel will ease cleaning, analogous to using a Teflon® coated non-stickpan. Surface energy of less than 35 dyne/cm is desired for this type ofapplications.

Work on enamel coupons and ceramic tiles has shown the ability of aninventive material coating to adequately coat ceramic or metallicsurfaces with a submicron thick coating. Mechanical interlocking isconsidered to be the major concern with this application due to therelatively rough surface morphology of the enamel surface. Therelatively inert surface chemistry of inventive material is expected tobe stable upon interaction with various food items at elevatedtemperatures in ovens.

Food processing equipments are sources for bacteria/biofilm attachmentand growth which can turn into a serious health problem. One of thereasons for bacterial adhesion is the surface roughness helping thebiofilm formation through mechanical interlock. Another is presence ofmoisture. Both these sources of bacterial adhesion can be eliminatedusing inventive material coating and inventive material coating alongwith an organic hydrophobic layer. Bacterial resistant coatings thus canbe formed by reducing metal surface finish for example, by a factor of 5that is down to the electropolish level using inventive materialcoatings. Inventive material coatings can also be used for cryomachinedsurfaces (in-lathe spray-coating and IR-lamp curing). Inventive materialcan also e used as an abrasion resistant coating on lenses and glassmirrors.

Inventive material can function as non-stick coating on polyester andother food packaging plastic substrates. As discussed, below,roll-to-roll coating process can be utilized along with flash curing toachieve high throughput of coated products.

Another embodiment of this invention is to use a low surface energylayer such as organo silane, fluorosilane, organic molecules or polymersover the inventive material coating. This top layer can help in severalways including, but not limited to, reduction or elimination ofvarnish-like residue formation from food at cooking temperatures. Theseovercoats can be reapplied very easily by spray techniques.

Another embodiment of this invention is use of the inventive material asa spray product for commercial or household applications.

The technical barriers are significant to yield uniform coverage at filmthicknesses targeted (50-500 nm) using spray formulations. Mostcommercial spray coatings are relatively thick (few mils) and theprocesses are not amenable to developing high quality thin films. Thedegree of difficulty in developing suitable aqueous formulations, whichare preferred for safety and environmental reasons, is even greater thanthe alcoholic counterparts. Many hazards, toxicity, flammability, waste,related to the use of alcohol-based precursors would be alleviated.Aqueous formulations do not offer suitable wetting properties and theshelf stability of aqueous formulations are poor.

Another embodiment of the present invention is the precursormodifications to develop suitable spray formulations. Aerosol technologyis very amenable to various environments and users. Deposition of acontinuous, submicron thick film will be our biggest challenge in priorart. In addition, the atomization parameters that will vary based onsolvents and additives, surface coverage and wetting will vary fromsubstrate to substrate.

Another embodiment of this invention is the development of water-basedor water-ethanol mixture based inventive material solution. Wettingproperties can be improved by enhancing the polymeric nature of theprecursor solution via increasing polymer chain lengths by refluxing. Tofurther improve wetting small amounts (<2 wt %) ofcommercially-available surfactants and/or a mixture of water/alcoholsolvent can be used. Useful surfactants lower the surface tension ofwater, but are also chemically compatible with the precursor, and duringcuring (ease of solvent removal). Good quality coating can be applied tosolid substrates including, but not limited to, enamel, stainless steel,glass, ceramics and polymers with known aerosol techniques for alcoholicsolutions.

This invention can also provide an inexpensive, and rapid process tofinish the surface of silicon carbide optics. This new process issuitable for a wide variety of types of SiC, and can be used,independent of fabrication technique, to planarize SiC surfaces forspace- and land-based optical systems. Due to a low melting eutecticbetween aluminum phosphate and silica, inventive material coatings canplanarize the surface of SiC through a reaction with the substrate.

The use of inventive material thin films, either alone or through thereactive mechanism, to planarize the SiC reflective is a significantimprovement over current surface finishing techniques in terms ofreduced cost and reduces time required. The surface roughness of a pieceof sintered SiC was reduced over 100-fold (1 μm diamond abrasive surfacepolish to 2.7 nm rms roughness) by an investment of approximately 0.5man-hours. Additionally, thin coatings of inventive material can be usedto planarize surfaces of aluminum mirrors or silver mirrors as well asother non-optical substrates, without relying on the reactive mechanism.

Advantages of an inventive material based surface finishing processinclude:

-   -   Substantially reduced cost to achieve a smooth (<10 nm rms        roughness) surface    -   Reduced time required to produce an optical quality finish    -   Applicable to many ceramic as well as metal optical systems,        regardless of ultimate mission    -   No significant investment of processing equipment will be        required to achieve an optical quality finish    -   The process of depositing inventive material is extremely simple        and versatile.

The precursor solutions used to develop the coatings have low-viscosity,are clear and stable (shelf life extends over years), and are suitablefor dip and spin coating processes.

-   -   The surface obtained is glassy in nature and conventional or        MRF-based finishing techniques can be used to further decrease        surface roughness

Thus the present invention offers the opportunity to obtain a glassylayer on ceramic surfaces via heat treatment or direct deposition ofinventive material films which can be polished with similar proceduresused for glass mirrors while exploiting the superior mechanical andthermal properties of ceramics such as, but not limited to, siliconcarbide and silicon nitride.

Without wishing to bound by any theory, inventive material coatings onsilicon carbide appear to promote the formation of analuminophosphosilicate glass upon high temperature anneal. It is knownfrom the prior art that there is an eutectic in the AlPO₄—SiO₂ system at70 mol % SiO₂ which melts at 1400° C. Coatings of inventive materialapplied on sintered SiC appear to form a glassy phase after 1400° C.anneal. Without wishing to bound by any theory it is believed that theoxidation of SiC to SiO₂ provides the silica to form the reaction phase.The phase on the surface appears to be glassy, lacking a crystallineappearance. Under the optical microscope and with surface evaluation bySEM, it is apparent that the surface is significantly smoother than theoriginal substrate or the uncoated, annealed sample.

Hexyloy SiC was polished with 1 μm diamond slurry, resulting in asurface finish on the order of 1-3 mm. Hexyloy SA is 99% pure sinteredSiC. Hexyloy is somewhat porous (compared to CVD SiC), and these poreswere effectively sealed with the inventive material coating. Thissubstrate was coated and heat treated, along with an uncoated sample.After heat treatment, the coated sample was highly reflective,indicating a smooth surface. The rms roughness of the coated sample wasreduced to about 2.7 nm as measured by AFM. The uncoated, annealed andas-finished surfaces were significantly rougher and maintained arelatively porous surface morphology. Not including initial polishing,the procedure of coating and heat treating took approximately 0.5man-hours of time. (In this case, the polished (1 μm diamond abrasive)silicon carbide substrate was cleaned ultrasonically, then dip coatedwith inventive material solution, then heat treated in a laboratoryfurnace.) Without wishing to bound by any theory, the aluminum phosphatepresent in the inventive material is believed to react with silicaformed from the oxidation of the silicon carbide. In addition, nocracking was observed upon cooling suggesting a relatively good CTEmatch for the glass with the SiC substrate.

In addition, the inventive material enabled excellent protection of SiCfrom oxidation at elevated temperatures. Substantial reduction in weightgain was observed for the coated material as compared to as-receivedsilicon carbide after exposures up to 1400C for over 100 h.Incorporating silicon into the inventive material may serve as thesilicon source to form the aluminosilicate-phosphate glass compositions.Some loss of phosphorous is observed after high temperature anneal,however, the surface appears well sealed to afford environmentalprotection. In a modified method, other substrates can also be used byfirst depositing SiC coating by any of the known methods, including CVD,and then treat the surface with inventive material as described. C/C andC/SiC composites used in high temperature applications requireprotection against oxidation. Such treatments can be considered toenhance protection of these and other non-oxide and oxide compositesystems.

The present invention can be employed to promote good adhesion betweenan organic polymer coating and the surface of metals that may or may notdevelop an oxide layer. The phosphate and aluminate groups cancovalently bond with a metal atom at the metal surface. The inventivecoating composition may also contain at least other organic or organosilane or organo phosphate overlayers for improving bonding withorganics and polymers. Alternatively, other organic or organo silane ororgano phosphate layers having at least one reactive moiety which iscapable of bonding with an organic resin may be applied separately asanother over layer. The invention is particularly useful for providing ainventive material interface which promotes adhesion between arelatively inert metal surface, such as a noble metal surface, e.g.,gold, silver, platinum, palladium, iridium, rhenium, ruthenium andosmium, and an organic polymer coating. Adhesion promotion effect ofinventive material coating is not limited to metal-polymer materials.This can include metal-ceramic, ceramic-polymer, glass-polymer,glass-ceramic, ceramic-glass, ceramic-ceramic and other systems as well.

Present invention also related to the iridescent, non-iridescent,anti-tarnishing and high reflection (high reflectance) coatings onstainless steel and like surfaces. Protective oxide coatings onstainless steel with thickness less than <1 micron, exhibit iridescentcolors due to difference in the refractive index of substrate to coatedlayer. Inventive material amorphous aluminum phosphate thin coatings onstainless steel are effective against oxidation at elevated temperaturesand hence anti-tarnishing. They also retain or improve the reflectivityof the coated metal surface. This coating also shows iridescent colorswhich can exploited as decorative coatings on articles. Without wishingto be bound by any theory, inventors believe that the iridescent colorobserved on coating depends on the chemistry, thickness and theuniformity of coatings.

Inventive coating material can be used along with under coats andovercoats to modify the reflectivity, iridescent, gloss and otheroptical effects due to thin coatings. Any phosphorus material thatcontains a phosphorus atom with a valence of 3 or 4 may be used as undercoat. The phosphorus compound can be organic or inorganic. Organicphosphate can be, such as, but not limited to organic phosphites,phosphates, phosphonates, hydrogen phosphites, hydrogen phosphates,polyphosphates, polyphosphonates, phosphate esters, phosphite esters,phosphines, alkyl chlorophosphines, chlorophosphates, and mixturesthereof. Inorganic phosphates can be, such as, but not limited to, metalphosphates, phosphoric acid mixed with suitable solvents, phosphoruspentoxide solutions, phosphorus halides, phosphorus and mixtures thereof. Over coats can be organic or inorganic or hybrid coatings. Organicover layers can be such as, but not limited to, self assemble monolayersof organic molecules or polymers. Siliane based coatings can also beused as over coatings. Inventive material itself can function as underas well as over coat. Inventive material coating also can have organicor inorganic additives. Inorganic additives can be metal ions such as,but not limited to, silicon, iron, zinc and manganese and or mixturesthereof. Nano-crystalline oxides, such as, but not limited to, zincoxide, titanium oxide and mixture thereof.

Inventive material coating can be made as a porous bulk material usingorganic templates such as polymers and large organic molecules.Inventive material with designed porosity can be used as a low kdielectric material and as a coating for silicon, gallium arsenide andother semiconductors, particularly for silicon carbide which is a hightemperature semiconductor and needs a thermally stable low k dielectriclayer. Spin-on glass as the process can be used deposit the inventivematerial layer that can also serve as an effective diffusion barrier.Porosity in the inventive material can be designed to be in thenanoscale so that the coating can maintain good mechanical properties.The organic content in coating composition can be modified to helpimprove toughness of the layer as well as to minimize cracking due toprocessing.

Sealing surface defects on glass, polymer and other related substratesused in semiconductor, solar cells, flexible displays can be effectivelyachieved using inventive material coating. Further, inventive materialcoatings can act as a barrier layer for diffusion of oxygen, moisture,sodium and other environmental factors.

The inventive material films can also useful in seal defects on quartz,glass and other substrates used as photoblanks in semiconductorindustry. The inventive material can also be etched in submicron scales,if required, using chemical or physical methods.

Iridescent glass coatings on steel or other surfaces can enhance theaesthetic value of a surface. Inventive material when coated on metallicsurfaces shows iridescence. Such coatings may be applied as art form,signs, part labeling, and many others.

It is a very difficult task to achieve continuous and crack free coatingin micro scale levels using solution based processes. It is moredifficult with architecture containing gaps and non-uniform surfacesstructures. In the prior art such coatings are achieved viaspin-on-glass coating of silicates, borosilicates and phosphosilicatesin semiconductor devices. However they have drawbacks like cracking andsodium diffusion and other problems. Semiconductor industry is lookingfor cost savings technologies which can replace the existing ones alongwith reduced cost of manufacturing, equal or higher performance andcombining multiple properties in a single material.

Coating should be thick and dense enough to prevent or limit sodiumdiffusion as well as should be crack free. Both combinations aredifficult to achieve using sol-gel coating techniques. With suitablemodification of coating techniques and composition of the inventivecoating material, these conditions can be achieved. The coating shouldbe able to planarize the coated substrate in order to build upmultilayers over the coatings. The coating materials should be stablewith high dielectric breakdown strength. Liquid surface tension effectsthat might be creating problems in achieving continues coverage orcoating on edges can minimized or removed using suitable additives,composition, viscosity, and concentration of inventive materials andmodified inventive material precursors.

The inventive material can be used as a spin-on-glass coating onsubstrates like, but not limited to quartz, silicon, silicon carbide,gallium arsenide and other substrates. An inventive material coating hascharacteristics such as, but not limited to, insulating, low dielectricconstant, planarizing and ionic barrier etc. which are essential forcoating on semiconductor devices. Similar coatings can be formed anytype of non-uniform surfaces irrespective of their surface chemistrybecause of the strong adherent nature of inventive material. Inventivematerial and its modified precursors can be used both asconformal-coating as well as planarizing-coating depending the coatingthickness and methods. Inventive material coating can also be combinedwith other planarizing techniques like MRF or CMP to achieve betterquality surfaces if needed. The coating also can protect semiconductordevices from problems arising from sodium diffusion from handlingenvironments. The inventive material and modified inventive materialprecursors can be used as flowable gap-fill materials usingspin-on-glass technique. Thus inventive material can be used to developflowable Spin-On insulator. Based on spin on glass technique, small andproducts with complex geometry such as but not limited to, fasteners,can be coated with inventive material for protection against galvaniccorrosion (for example, steel fasteners into an aluminum chasis) anddegradation from solvents, chemicals, and other environmental attack.

Metal and polymer foil substrates are used in various applicationsincluding displays, photovoltaics, heat shields, and others.Thermally-Stable coating of the inventive material can be depositedcontinuously on these substrates for imparting desirable properties.Multifunctional nature of the inventive coating material can providesubstantial benefits over prior art materials at low processing cost andhigh throughput. For example, the inventive material can be deposited toimpart electrical isolation and to provide a smooth surface. This avoidsthe commonly-used expensive PVD or CVD process to deposit alumina layerwith further coating layer/s required to impart sufficientplanarization. For the food packaging industry, the inventive materialcan be deposited on plastic substrates in a continuous roll-to-rollmanner and impart non-stick properties against food. The inventivematerial will also provide suitable barrier properties against gasesthat diffuse in or out of the food packaging material.

Vacuum based coatings inherently contain pin-holes and other defects duethe processing methods. Thin inventive material coating on vacuum basedcoatings can remove these defects and can be effectively increase thebarrier properties of coatings. Further, an inventive material coatingcan act as a planarizing template for developing other types ofcoatings.

Devices, especially micro- and nano-fluidic devices use molds made froma plastic material by below molding, dip molding, film insert molding(FIM), gas assist molding, reaction injection molding, resin transfermolding, rotational molding, structural foam molding, thermoplasticinjection molding, vacuum assist resin transfer molding (VARTM), vacuumbag molding, vacuum forming, injection molding, compression molding,extrusion blowmolding, thermoforming, UV reaction molding or embossingor other molding processes. These devices find application in a varietyfields such as, but not limited to biomedical devices, opticalcommunication systems (where part dimensions are under 1 mm andtolerances are under 1 μm) and others. Micro-optical parts withnano-structured surfaces, and large-area automobile windows with perfectclarity and long-term resistance to attrition, are at the cutting edgeof plastics processing technology. Microfluidic lab-on-a-chip systemshold great potential for many laboratory applications, includingclinical diagnostics and life sciences research. A number of devicesthat are well suited to handle the tough requirements of real clinicalsamples such as whole blood and other bodily fluids are being developed.The devices can be used in stand-alone applications as self-containedpassive disposables for qualitative and semiquantitative assays andseparation applications, or they can serve as components ofsophisticated instrument-based systems.

Quick and efficient release of a molded part from the tool is the key toany efficient molding process. During processing, high heat resins, forexample, polyetherimides, may reach temperatures over 700° F. resultingin decomposition of many standard mold release additives. Newhigh-temperature mold releases are needed for open the processing windowallowing for better reproduction of surfaces in parts and faster moldingcycles with reduced scarp in parts. The molding surfaces include metals,silicon and others.

Plastics-processing also requires that the mold release coatings used inmolds to be a permanent one. Other goals include better coatings forwear resistance, corrosion resistance, and improved resin flow.Successful coatings yield improved part release and part quality,protection of the mold against wear from abrasive materials, and reducedbuildup of deposits, allowing faster mold cleaning. Significant economicbenefits are also gained by eliminating downtime caused by partssticking in molds, broken ejector pins, and improperly working machineparts such as backflow valves. The net effect can be decreased cycletimes and longer maintenance intervals.

For example, a P-20 mold with a hardness of 40 Rockwell C and a cavityperimeter of 12 by 18 inches, was molding parts that were reluctant torelease despite a Teflon-nickel coating, lapping compound and wire-brushtreatment, and a mold release application prior to every shot. Inaddition, the final step in the part's 72-second cycle involved a workergingerly extracting it from the mold by hand while trying not to causeany distortion or warpage. Peeling a part proved to be time-consuming,and costly. Scrap rates ranged from 30 to 40 percent. It has beendetermined that a finish of 6 μm on the tool's surface was necessary fora speaker grille application of this kind to release automatically.Using conventional EDM technology, it is possible to achieve a finish ofonly 12 to 14 μm after 150 hours of finishing work. After 150 hours, anybetter surface finish than that could be achieved.

Inventive material technology may be useful as a permanent mold releasecoating. Inventive materials can be beneficial in reducing the surfaceroughness below 6 μm with the fraction of the work and cost thatrequires for conventional polishing techniques. Along with reducingsurface roughness, surface energy of the coated surface also can bereduced with a over organic layer which can be self assembled or a layeron its own. Improved energy and finish with inventive material coatingon 12 micron surface could be very beneficial for plastic andmicrofluidic industries. Various types of materials such as polymers,metals, alloys, high temperature stable polymers, etc., are used inmolding, depending upon application requirements.

A window on military aircraft, whether it is a canopy on a fighter jetor the covering on an infrared sensor must be exceptionally sturdy towithstand being battered by debris at high velocities, yet remaintransparent to allow the pilot to see out, or the infrared signal toreach in. Windows made of conventional yttria tend to crack in flightconditions. Inventive material can be used as a medium to disperse suchnanoparticles in high loads and applied as coating. This can serve as acost-effective method for coatings on infrared store scanners and otherapplications. It can also help in extending the lifetime of canopies onfighter jets.

Various other uses and applications of the present invention include thefollowing:

Inventive material coatings can be used in thermal spray coatingindustry. For example, inventive material can be used as an infiltratingsealer for MCrAlY-class turbine blade spray-coatings and feedstock forcold-spray coating applications.

Inventive material coatings with or without hydrophobic over layer canbe used a low-wettability windshield glass coatings.

Low-temp amorphous inventive material coating/Al₂O₃ coatings can be usedin various fields including but not limited to electronics, textiles andpolymers.

Inventive materials can be used as anticatalytic coatings for Ni-richcomponents used in hot gas handling systems.

Inventive materials can be used as infiltrants for powder-metallurgycomponents (sinter-hardenable).

The inventive material can be used in Fuel-cell and gas reformingcomponents (hot surfaces) as a coating composition.

Inventive material coatings on metals can be used as interface layersfor adhesion improvement along with corrosion protection and improvementof lacquer adhesion. Inventive material coatings are also useful foropto-electronic and other sensors with regard to their low dielectricproperties. Electrically insulating inventive material layers are needfor the design of solar cells on metallic foils. Inventive materialcoatings act as a protection layer between the electrical back contactof the solar cells and the conducting substrate.

Thickness requirement of inventive material coating varies with theapplication.

Following table lists some of the application along with a useful,non-limiting required layer thickness.

Application Layer Thickness Optical layer stacks for highly reflectiveand 10 nm-200 nm antireflective coatings Transparent gas barriercoatings on plastic webs 30 nm-100 nm Abrasion resistance coatings onpolycarbonate sheets   4-6 microns Interface layers for adhesionimprovement (several  5-20 nm substrates) Conversion layers on steel(corrosion protection, 0.3-0.4 microns lacquer adhesion) Dielectriccoatings (sensors, back side protection of   2-5 microns solar cells)

Inventive material coatings can be very beneficial for regulating theproperties of variety of substrate surfaces. For example, glass slidesmanufactured by different companies may not have the same composition.Even for the same manufacturer different batches of glass slides may notmatch exactly. For example, the surface roughness might vary dependingon the treatment these samples underwent. It is very critical in someapplications to have almost identical surface characteristics insamples, like for example, in the case of micro arrays. Inventivematerial coatings can provide uniform surface characteristics forexample, uniform surface chemistry uniform surface roughness etc.

Metals and alloys such as titanium, Ti₆Al₄V, CoCr are widely used asmaterials for orthopedic implants due to their excellent mechanicalproperties and nontoxic behavior. The high strength and fatigueresistance as well as availability, easy processing and low cost explainthe important roles gained by metals in implantology. A particularimportance is given to titanium and its alloys and CoCr alloys, becausethese metals may be integrated into surrounding tissues, and especiallyhard tissues, alloys and exhibit chemical and mechanical bonding,indicative of good biocompatibility/histocompatibility andbiofunctionality. Different and high rates of corrosion influence thechoice of an implant material, since fretting corrosion among others maycontribute strongly to the production of wear particles which might leadto a particle disease and to implant loosening consecutively. Affinityof metallic surfaces to microbial contaminants and biofilms is also amajor problem. The rate of implant infection, necessitating the riskfulexchange of the implant, even in good clinics, can reach 2%-3%. Thecareful design for first time implants and for exchange implants has toface the problems of stress shielding and loss of bone stock. Most ofthe prior art coatings are cracked and has poor reliability ofglass-metal interface. So, strongly adhering protective andbiocompatible coatings will be highly beneficial.

A variety of methods have been developed in prior art to modify thesurfaces of polymers, metal and alloys or other biomaterials used in thedevice industry. Examples include conventional coating processes such asspraying or dipping; vacuum deposition techniques; and suchsurface-modification technologies as diffusion, laser and plasmaprocesses, chemical plating, grafting or bonding, hydrogelencapsulation, and bombardment with high-energy particles.Traditionally, the goal was to achieve improved physical or mechanicalproperties in a component or device—for example, by adding a nonstickcoating to a catheter for easier insertion. Increasingly, however,surface modification also aims at inducing a specific desiredbioresponse or inhibiting a potentially adverse reaction. Low friction,hydrophilic, hydrophobic and other functional coatings are also neededfor invasive instruments, products and accessories used to treat carotidartery and bile duct blockages and peripheral vascular disease, and foruse with carotid artery stenting, guide wires, catheters, etc.

The present invention relates to the development of protective,functional and biocompatible coatings based on the inventive material.Compositions of the inventive material can be tailored to fit the needfor coatings on medical devices and implants. Inventive material coatingon metallic or polymer substrates can decrease the coefficient offriction to a considerable extent. After the coating and curing theinventive material surface be made hydrophilic or hydrophobic. Usingself-assembly for organic layers or coating of organic layers oninventive material coating suitable functionalities can be imparted.Hydroxyapatite or other bioactive nano particles can be incorporated into the inventive material coating to improve biocompatibility. Bioactivelayers for example, hydroxyapatite can be deposited using vacuum, plasmaor sol-gel based coating techniques. In this case, inventive materialcoating can act as a adhesive layer to improve adhesion between metal orpolymeric medical device substrates with bioactive materials.

Inventive material coatings can effectively prevent or reduce thedevitrification of fused silica or quartz and other amorphous materialsused in, for example, surgical probes, lighting products etc. fromreaction with alkali and other species.

Boundary lubrication is known to enhance the lubrication properties ofmany systems. Present invention deals with the deposition of thealkylfluorosialnes on the surface of the inventive material coating andthe stability of such organic layers. A smooth surface is highlydesirable for low friction characteristics, but requires extensivesurface preparation, and the presence of surface defects such as pits onalloy surfaces limits the quality of surface finishes. A well-adhered,abrasion resistant coating which can planarize the surface will be ofgreat utility for tribological applications. Inventive Material film canalso prevent the corrosion of the substrate both from the lubricant andfrom the atmosphere. The hermetic inventive material coating can protectthe substrate from the lubricant and also from corrosive species presentin the atmosphere.

Embodiments of inventive material coatings on polymers and likematerials offers a) excellent protection against light radiation (forexample, UV radiation), b) excellent protection against damaging acid,alkali, organic solvents and other chemicals c) adequate sealing ofdefects (such as pits) and cover particles on polymeric surfaces suchthat the coating planarizes the coated surface and reduces the surfaceroughness (d) excellent barrier against inert gases (e.g. oxygen,nitrogen, hydrogen), to chemically active gases (e.g. water, carbondioxide), and to liquids and vapors (e.g. aromas, fine chemicals,gasoline), (e) excellent barrier against atomic oxygen, nitrogen,oxygen, hydrogen and other elements found in low earth orbits ordeveloped in laboratories, (f) excellent protection against mechanicaldamage of the polymeric surfaces occurring from a variety of sources(for example, customary handling of the material, impact with highvelocity materials etc.) (g) excellent protection against oxidation (h)excellent protection against corrosion (i) excellent protection againstmoisture, (j) excellent protection of bio-medical polymers used inmedical applications against corrosion from body fluids and chemicalsand microbials (k) to reduce the coefficient of friction of the polymersurfaces through planarization and (l) increase the abrasion resistanceof coated polymer surfaces. Among these, a relevant and innovativeattribute, without wishing to be bound by theory, is the ability of theinventive material to promote formation of a dense, continuous, smoothand strongly adherent inorganic or predominantly inorganic orinorganic-organic composite coatings.

With regard to examples of polymers forming a plastic film or substance,cellulose esters (e.g., triacetyl cellulose, diacetyl cellulose,propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose,nitrocellulose), polyamides, polycarbonates, polyesters (e.g.,poly(ethylene terephthalate), poly(ethylene naphthalate),poly(1,4-cyclohexanedimethylene terephthalate),polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, poly(butyleneterephthalate), polystyrenes (e.g., syndiotactic polystyrene),polyolefins (e.g., polypropylene, polyethylene, polymethylpentene),polysulfones, poly(ether sulfone), polyarylates, poly(ether imides),poly(methyl methacrylate) and poly(ether ketones) are included.Triacetyl cellulose, polycarbonates, poly(ethylene terephthalate) andpoly(ethylene naphthalate) are preferred. Packing materials consist ofpolymers, for example polypropylene PP, polyethylene PE, polyamide PA,PET, and laminate films made from various polymer materials, e.g. PP/PE,PET/PP, PET/PE, PE/PA.

The plastic layer used in flexible display devices can be made from forexample, polyesters, polycarbonate, polyvinylbuterate, polyethylene andsubstituted polyethylenes, polyhydroxybutyrates,polyhydroxyvinylbutyrates, polyetherimides, polyamides,polyethylenenaphalate, polyamides, polyethers, polysulphones,polyvinylacetylenes, transparent thermoplastics, transparentpolybutadienes, polycyanoacrylates, cellulose-based polymers,polyacrylates and polymethacrylates, polyvinylalcohol, polysulphides andpolysiloxanes.

The substrate also can be in the form of lamination, the plastic layerof the composite is coated onto the glass layer by any suitable process.That is, it is possible to consider the different situations (i) whereplastic exists already as film and is laminated to the glass and (ii)where plastic is not in film form but is coated onto the glass by dip,spray, and other processes. The pre-polymers mentioned above, forexample, are amenable to case (ii). However, also several of the otherplastics mentioned above can be coated for case (ii). In this instancethe polymers can be coated onto the glass principally by: coating fromsolution, from a melt or as pre-polymer.

The substrate can also be any organic, preferably organic polymershaving high temperature thermal stability. The polymers can bethermoplastics or thermosets, preferably high temperature thermoplasticssuch as polyimides, polyamide-imides, polyetherimides, bismalemides,fluoroplastics such as polytetrafluoroethylene, ketone-based resins,polyphenylene sulfide, polybenzimidazole, aromatic polyesters, andliquid crystal polymers. In addition polyolefines, particularlycrystalline high molecular weight types can be used.

Curing can be effected by any methods which can result in condensationand formation of Al—O—Al, P—O—Al groups. For example, thermal treatment,exposure to UV light of relevant frequency, increasing the pH of thesolution above 3, exposure to IR radiation, exposure to microwaveradiation, exposure to chemicals that can hydrolyse P—OR groups,addition of suitable chemicals which can increase the condensation rateor combination of any of the above methods.

Adhesion of inorganic coatings to a polymer is a major problem thatlimits the use of coatings reported in prior art. Measuring adhesion bytape test was performed on polyimide samples (similar to ASTM D-3359test) coated with inventive material. 3M™ Scotch™ tape was applied overthe coating and then removed rapidly. There was no removal or loss ofadhesion of the inventive material coating on polyimide film. Opticalmicroscopic observation of inventive material coated polyimide filmsafter bending by 180° also did not show any cracking of coating. Theseresults indicate the strong adhesion of Cerablak™ coating on polymers.Phosphate based coatings are known to show strong adhesion on polymers.For example, calcium phosphate on polyethylene andpoly(tetrafluoroethylene) showed adhesion strength of 6.4 and 5.8 MParespectively. With out wishing to bound by any theory we believe thatthe strong adhesion is presumably due to the formation of C-0 bondbetween phosphate groups and polymer interface during curing of thecoating. The adhesion can also be improved by pre-treating thesubstrates with Ar ions. Inventive material precursor solution is mildlyacidic and will not damage the acid sensitive polymeric substratesurfaces during coating process.

The organic groups attached to phosphorus in the precursor solution canbe reduced or eliminated completely by replacing P—OR groups with P—OHgroups. However, any chemical change in the precursor solution mayaffect the condensation and formation of the thin film. Some embodimentof the inventive precursor solutions can retain the aluminophosphatecomplexes with characteristic [O═P—O—Al—O—Al] bonding. With out wishingto bound by any theory we believe, the organic content can be reducedsignificantly by increasing the relative content of “P—OH” species. Inaddition to using water or other non-alcoholic chemicals as solvents,the organic content may be reduced by using sterically hindered alcoholsfor example, iso-butyl alcohol as a solvent for aluminum nitrate. Thereaction rate of iso-butyl alcohol with condensed phosphate (P—O—P)groups is low. Even if P—O-i-Bu groups are formed in solution they canbe readily removed on refluxing, forming 2-methyl propene, which is agas at room temperature (b.p. 6.6° C.).

Wetting of low surface energy polymers with alcohols is a challenge.Adhesion is of concern since high curing temperatures may be needed toimprove adhesion. In the case of polyimide films adhesion of inventivematerial coating shown to be excellent with out any surface treatment.In the case of poor coating adhesion with some polymers, surfacemodification of the polymers can be adopted. Several techniques, such asdeposition of primer, use of surface assembled monolayers SAMs, oxygenplasma etching and sulfochromic bath treatment can be used to improvewetting. Inventive material coating can also be used a primer oradhesion promoting layer for other metallic, polymeric and inorganiccoatings.

Underlayers and overlayers can be selected from any organic polymercoatings, inorganic-organic hybrid coatings, or metallic coatings. Theselayers also can be formed from inventive material of same of differentcomposition. These layers also can be formed by inventive materialprecursor modified with any inorganic or organic functional agents. Forexample, UV absorbers.scatterers like ZnO, CeO₂ or TiO₂ oxides for UVradiation protection, Ag ions for antimicrobial activity, transparentmetal oxides like ITO for electrical properties, SiO₂, Al₂O₃, ZrO₂ toimprove mechanical properties, or photocatalytic species like TiO₂ toimpart hydrophilic properties. Several layers of these under and overlayers can be built depending upon the requirements. Inventive materialcoating can planarize the polymer surface along with suitable modifiedrefractive index can help in reducing the scattering of light fromcoated polymeric substrates.

EXAMPLES OF THE INVENTION

The following non-limiting examples and data illustrate various aspectsand features relating to the composites, articles and/or methods of thepresent invention, including the use of various aluminum phosphatecompounds and related compositions therewith, as are available throughthe synthetic methodologies described herein. In comparison with theprior art, the present compositions, composites, articles and/or relatedmethods provide results and data which are surprising, unexpected andcontrary thereto. While the utility of this invention is illustratedthrough the use of several composites/articles and aluminumphosphate-based coating compositions used therewith, it will beunderstood by those skilled in the art that comparable results areobtainable with various other composites/articles and coatingcompositions, as are commensurate with the scope of this invention.

Example 1

One preferred method for depositing an amorphous aluminum phosphatecoating is with a clear chemical precursor solution, with the solutionpreferably containing an aluminum salt and phosphate esters in anorganic solvent. A solution used to deposit amorphous aluminum phosphatecoatings with a 2 to 1 aluminum to phosphorus ratio is made bydissolving 264 g of Al(NO₃)₃.9H₂O in 300 mL ethanol. In a separatecontainer, 25 g P₂O₅ is dissolved in 100 mL ethanol. These solutions aremixed together. The resulting solution is diluted with ethanol to aconcentration of 0.2 moles Al/L solution. This solution is used todeposit amorphous aluminum phosphate coatings on substrates.

Example 2

A solution used to deposit amorphous aluminum phosphate coatings with a4 to 1 aluminum to phosphorus ratio is made by dissolving 528 g ofAl(NO₃)₃.9H₂O in 300 mL ethanol. In a separate container, 25 g P₂O₅ isdissolved in 100 mL ethanol. These solutions are mixed together. Theresulting solution is diluted with ethanol to a concentration of 0.2moles Al/L solution.

Example 3

A stainless steel plate cleaned with detergent and water followed byultrasonication in methanol. Dipped in solution prepared in example 1.Dried using a heat-gun. Dried sample is heated at 400° C. for 1 min andcooled to room temperature. The cured stainless steel plate surfaceshowed strong iridescence. This type of inventive material coatings maybe applied as decorative coating on articles.

Example 4

A stainless steel plate cleaned with detergent and water followed byultrasonication in methanol. Then, dipped in an alcoholic solutionconsisting of phosphate and aluminum mixture. Then, dried usingheat-gun. Dried sample is heated at 400° C. for 1 min and cooled to roomtemperature.

Example 5

Infrared Reflectance-Absorption Spectroscopy of the sample prepared inexample 4 is recorded using Perkin Elmer Spectrum One spectrometer using80° grazing angle accessory (FIG. 1).

Example 6

An over coat of precursor solution prepared in example 1 is applied bydip coating on the sample prepared in example 2. Then, the sample isheat treated at 500° C. for 15 minutes and cooled to room temperature.Uncoated part of the plate is discolored due to oxidation. Coated partis shiny and retained silver color. The precursor solutionconcentration, compositions and coating conditions are strongly dependon the surface morphology of coated surface. Thus, iridescence effect ofinventive material coating may be removed by suitably modifying theprecursor and coating methods.

Example 7

Infrared Reflectance-Absorption Spectroscopy of the sample prepared inexample 6 is recorded using Perkin Elmer Spectrum One spectrometer using80° grazing angle accessory (Fig.).

Example 8

On the surface of the stainless steel coated with inventive materialfinger print impression is made by pressing thumb on the surface. Then aclean cloth is used to wipe the impression. The thump impression can beremoved very easily from the coated surface leaving aestheticallypleasing clean surface. It is not possible to remove finger printimpression from the uncoated surface using similar cleaning method.

Example 9

Stain resistant effect of inventive material coating on solid substrateshas been demonstrated in this example. Variety of materials such asKetch-up, H2O+NaCl, Tomato, Lemon, The, Coffee, Milk, Acetic acid,Citric acid 20%, Lard+oleic acid, Jam, Butter, Olive oil and other itemsare left on a inventive material coated stainless coupon and allowed todry at room temperature and 90° C. Then washed with water and thenvisually checked for any stain on the coated surface. Inventive materialcoated surface did not show any stain.

Example 10

Inventive material coated stainless steel samples prepared in example 5is tested for pencil hardness. The pencil hardness found to be above 6H.

Example 11

The reflectivity of the inventive material coated surfaces was measuredbefore and after heat treatment up to 700° C. The reflectivity wasretained by the coated surface as compared to uncoated control sample.

Example 12

A small crystalline alumina (Sapphire) sample cleaned with deionizedwater, acetone and methanol. Then dip coated using precursor solutionprepared in example 2 (4:1 Al/P ratio). The withdraw rate of dip coatingis 2 cm/sec. Then, cured at 800° C. for 10 minutes. A transparentcoating resulted.

Example 13

TEM image of inventive material coating on Sapphire shows the hermetic,dense and uniform inventive coating (FIG. 3). Electron diffractionpattern obtained from the inventive material coating shows the amorphousnature of the coating. Inventive material film is uniform with athickness ˜140 nm. High resolution TEM showed typical amorphous contrastin the film. There is an interfacial layer (−5 nm) between inventivematerial and sapphire.

Example 14

Testing of partially inventive material coated enamel coupon showevidence for relative ease the removal of tomato sauce cured at 300° C.for 15 minutes from the coated region compared to from the uncoated areausing only water and a soft cloth (FIG. 4). This residue appeared to bewell bonded to the substrate when observed under optical microscope.

Example 15

Uncoated SiC surface with 1 μm polish and inventive material coated SiCafter heat treatment, showed reflective surface as compared to uncoated(FIG. 5).

Example 16

AFM images of inventive material coated, heat treated SiC, showingextremely smooth surface (FIG. 6).

Example 17

Based on the hermetic nature of inventive material films observed for anumber of metal, alloy, and glass substrates, it is expected thatinventive material can serve well to seal microscale surface defects onpolymers. FIG. 7 shows an AFM image of a metal alloy surface coated withinventive material demonstrating the significant planarization effectinduced by the film. A greater than 4× decrease in surface roughness isseen with the presence of the film.

Micron-scale surface defects on metal surfaces (even after polishing tosub-micron finish) serve as initiation sites for oxidation. As the metalsubstrates get oxidized during high temperature oxidation, these smallsurface defects serve as initiation points for oxidation. These smalldefects become large pits. However, depositing a relatively thininventive material film sufficiently covers these defects so thatpitting is essentially eliminated. These results demonstrate thepotential for inventive material to seal off micron-scale defects(scratches, pits, etc.) on coated surfaces.

Example 18

A copper block 1″×3″ dimensions was cleaned in acetone and methanolsonication. Then dip coated in inventive material precursor solution.Dried in air and heat treated in a furnace at 200° C. for 15 min.Photograph shows the effect of inventive material coating after thisheat treatment (FIG. 8). Inventive material coated part is remainsbright and shiny On the other hand uncoated side is tarnishedcompletely. Similarly copper, brass and other metallic wires can also becoated with the inventive material and protected against oxidation andenvironmental damages.

Example 19

AFM image of glass slide coated with the inventive material is shown inFIG. 9 along with the uncoated glass. The inventive material coatedsurface is very smooth and rms roughness decreased an order of magnitudefrom the uncoated glass.

Example 20

Formation of crack-free coating of a ceramic material on a polymericsubstrate is a technological challenge because of large coefficient ofthermal expansion mismatch and the heat sensitive nature of polymersubstrates. Residual thermal stresses lead to film cracking, especiallyif the coating is cured at elevated temperatures. This can be minimizedif the coating thickness is kept to a minimum and increase the adhesionenergy of the film to the substrate. With inventive material both theseconditions can be achieved because of low viscosity and phosphate basedprecursor solution which readily decomposes upon pyroylsis at relativelylow temperatures. Optical image of inventive material coating onpolyimide composite showed the planarization effect on the coatedsurface. Inventive material also covers the defects and hermeticallyseals the surface without forming such cracks.

Example 21

Polyvinyl pyrrolidone, PVP (M.W. 630,000) is dissolved in inventivematerial precursor solution prepared in example 2. The amount of PVP insolution can vary from 0-100 wt %. The viscosity of the solutionincreases with increase in PVP content. The solutions can also beprepared directly by mixing PVP with Al(NO₃)₃ and P₂O₅ solutions. PVPwith other molecular weights also can be used.

Example 22

A polycarbonate sample (1″×1″) is dipped in sulfochromic bath for 30sec. Then washed with plenty of deionized water. Then, dip coated withinventive material precursor prepared in example 2. Dried the coatedsample with a heat gun. Then heat treated in an oven at 130° C.Transparent coating formed after curing for a period of time.

Example 23

A polycarbonate sample (1″×1″) is dipped in sulfochromic bath for 30sec. Then washed with plenty of deionized water. Then, dip coated withmodified inventive material precursor prepared in example 3. Dried thecoated sample with a heat gun. Then heat treated in an oven at 130° C.Transparent coating formed after curing for a period of time.

Example 24

Methylethylketone solution is dropped on the surface of inventivematerial coated polycarbonate film prepared in example 5. No reactionwith polycarbonate observed. This suggests the protective ability ofinventive material coating against chemicals and its good barriernature.

Example 25

Nano sized zinc oxide particles dispersed in a medium is mixed withinventive material precursor solution prepared in example 2. The amountof Zinc oxide can be varied. The solutions can also be prepared directlyby mixing zinc oxide with Al(NO₃)₃ and P₂O₅ solutions.

Example 26

In order to determine the curing state of the inventive materialcoating, FTIR Reflectance spectra of inventive material coated stainlesssteel foils were recorded as function of temperature and duration ofheat treatment (FIG. 10). Organic absorption peaks due to phosphateesters (1370, 1432, 1473 1720, 2987 cm⁻¹) decreases in intensity and asingle strong absorption near 1200 cm⁻¹ due to completely linked PO₄group appears with increase in curing temperature and time. As thecuring temperature increased, duration of heat treatment required can beshortened. Based on the FTIR data, curing temperature of 325° C. isneeded to obtain completely inorganic coating with some waterinclusions. A crack-free coating was obtained by curing one inventivematerial coated polyimide films up to 340° C. The curing temperature andstability of coating can vary depending on the substrate nature,thickness and pretreatment conditions. The curing temperature can alsovary depending on the composition of inventive materials precursorsolution. It is interesting to note that the FTIR data of the samplesheat treated at 200° C. for longer duration showed little change in theresidual water content in the coating which could indicate that thecoating is dense and hermetic enough even at 200° C. curing. Accordingto this study, a curing temperature of 200° C. should be sufficient toform protective coating on polymers. But, higher temperatures mayprovide better adhesion and the hermetic quality will be better.

Example 27

A clean stainless steel foil is coated with precursor solution preparedin example 1. Heat treated the sample in a furnace at above 800° C. forfew sec. Grazing angle infrared reflection spectrum of flash-curedinventive material coating (FIG. 11) shows the absence of organics andwater molecules and formation of completely cured inorganic metalphosphate layer. During this flash-curing process the surface coatingreaches the temperature above 500° C. while the substrate is below 250°C. This flash-cure technique is preferred for certain types of coatingprocesses such as roll-to-roll and thermally sensitive substrates suchas polymers.

Example 28

Polyimides are classified as organic resins and are used in engineeringapplications due to their exceptional heat and chemical resistance. Inthe semiconductor industry, these materials are primarily used assubstrates for flexible printed circuit boards and for integratedcircuit applications in the wireless, digital and the computerindustries. The surface finish of these materials has a direct impact ontheir performance and therefore optimizing these conditions is critical.Inventive material is coated on a cleaned polyimide film and cured at300° C. for 1 hr. SEM image of inventive material coated polyimide film(FIG. 12) showed crack-free nature of the coating. Also particles on thepolyimide surface are covered by inventive material coating.

Example 29

UV absorption reduction by 40% upon addition of nanoscale ZnO (<10 mol%) into inventive material coating. This example shows the effect of UVabsorber addition to inventive material. UV-Vis transmittance spectra ofinventive material and ZnO dispersed inventive material coated on asapphire plate (FIG. 13).

Example 30

Silica glass products containing inventive material coating or surfacetreatment can prevent silicate reactions with environment duringservice. The results of this example demonstrate this effect of aninventive material coating on a fused silica sample. A fused quartzsample is partially coated with inventive material and treated withsodium sulfate, 900° C., 15 h. Under this treatment conditions uncoatedfused quartz became opaque due to the reaction with sodium ions, whereas the inventive material coated part remain transparent, showing thebarrier effect of the inventive material coating against sodium iondiffusion (FIG. 14).

Example 31

Embodiments of the inventive material can also serve as a chemically andthermally stable bonding agent or adhesive. In these experiments,modified precursor solution was applied to one surface to be bonded, andthe other surface was pressed to the first, to ensure that the precursorsolution adequately covered the surface of both pieces to be bonded. Thetwo pieces were clamped together and heat treated to form the inorganicmaterial. The joints made showed relatively good bond strengthsconsidering the low level of effort in these preliminary experiments.Phosphorus content will effect both transmission and adhesive strength.The phosphorous rich composition of inventive material may show someabsorption in the IR range, due to the relatively high phosphoruscontent but bonding may be more stronger. Bonding experiments wereperformed on both glass and stainless steel coupons. The glass had anextremely smooth surface, while the steel had a #3 finish. Theseexperiments have demonstrated that inventive material based adhesivesare capable of bonding substrate materials of varying surface finish.

To provide further evidence of direct relevance to this application, ofsapphire plate (rectangular) was bonded to a ZnS disc coupon. The couplewas annealed to 450° C. in air for one hour to test the thermalstability of the joint. The materials remained well bonded suggestingthe robust nature of the inventive material adhesive. Transmissionspectral measurements of the bonded couple indicate good transparency inthe 3-5 μm range with decreased transmission above 6 μm due to theopacity of the sapphire (FIG. 15).

Example 32

The inventive material can be synthesized over a wide range of Al/Pratios (e.g., from 0.5/1 to 10/1 and to 25/1), including addition ordoping of other elements, such as silicon, which may be necessary toinduce specific functional properties. As seen in FIG. 16, a comparisonof transmission properties of two inventive material films of varyingcompositions on ZnS reveals that an Al/P ratio of 6/1 show negligiblephosphate absorption compared to a relatively-rich phosphate compositionwith silicon addition (silica also absorbs around the same region).However, because the good adhesion is provided by the phosphate species,a balance between transmission and high adhesion strength may need to befound. Thus, the Inventive material system allows for flexiblecompositional variation to tailor specific properties.

Example 33

Applications of Coatings on Polymers

Industry Function of coating Examples Aerospace Diffusion barrier,Antistatic Bathroom Mirrors, coating Lighting Covers, Protection againstspace Thermoformed Parts Trays environmental effects & Tables, WindowsAppliance Diffusion barrier against Consoles & Membrane moisture andoxygen Switches, Fascia Panels, Food Storage Containers, Printed Labels& Nameplates Automotive Protection against Bumper Assemblies, mechanicaldamages Glazing (erosion); easy-to clean and hydrophobic coating forwindshields Antireflective coating Antistatic coating Building &Protection against erosion General Glazing, Lighting Construction Easyto clean and Panel Glazing, Office hydrophobic coating Interiors,Privacy Glazing, Anti reflective coating Public Buildings, Roof Lights,Separated Walls, Skylights, Sound walls, Wall Panels, Windows Electric &Electrical insulation, Enclosures, Insulation Electronics diffusionbarrier Barriers, Printed Circuits Machinables Protection againstBushings & Bearings, mechanical damages (wear, Gears erosion)Maintenance & Protection against wear and Chute Liners, ConveyorMaterial erosion. Wear Strips, Fabricated Handling Coating of Parts,machine Guards, Thermoformed Trays Marine Protection against DivePlatforms, Exterior, mechanical damages Interior, Upholstery Hydrophobiccoatings Components Optical Media Moisture Barrier Displays - LCD, OLEDsPrinting Protection against Decorative laminates, mechanical damagesMembrane Switches, Nameplates, Overlays Safety Protection againstGoggles, Machine Guards Equipment mechanical damages Sign & DisplayProtection against Back lighted Signs, mechanical damages BuildingFascia, Canopies, Channel Letters, Ground Mounted Industrial Nameplates,LED Covers, Menu Covers, Pole Mount, POP Displays, Thermoformed Signs,Tradeshow Booths, Vending Covers, Wall Mounted Telecom & Protectionagainst Cell Phone Covers, Die-cut Business mechanical damagesInsulators, Keyboards & Equipment Easy to clean optical parts Keypads,Lenses & Covers, Monitors & Displays Transportation Protection againstBug Shields, Glazing, mechanical damages Interiors, Thermoformed Parts

Example 34

With reference to one or more of the preceding descriptions or examples,various composites and/or product components can be prepared using rollto roll or continuous manufacturing processes known in the art and aswould be understood by those made aware of this invention. Accordingly,coatings of the aluminum phosphate compositions described above and byway of the incorporated references (e.g., the Cerablak™ compounds,compositions and products available from Applied Thin Films, Inc. ofEvanston, Ill.) can be applied to a wide range of substrate materials.Such equipment apparatus and configurations are described more fully inU.S. Pat. Nos. 6,951,770 and 6,878,871, each of which is incorporatedherein by reference in its entirety.

Optionally, a substrate can be prepared by initial removal of loosesurface debris, followed by degreasing with a suitable organic oraqueous solution (e.g., acetone or detergent/water) using one or morespray or dip applications, with a water and/or alcohol rinse. A dryingoven (at temperatures ranging from about 50C to 500C) can be used toremove all solvents, employing flowing air, dry air, oxygen, nitrogen orany other inert gas for atmospheric sensitive substrates.

As described above and/or in conjunction with the incorporatedreferences, a precursor solution of an aluminum phosphate compositioncan be sprayed on the substrate. Alternatively, the substrate can bedipped into one or more baths or reservoirs of a precursor solution. Ifboth, multiple or all sides of such a substrate are to be coated, one ormore spray nozzles can be configured, accordingly. Alternatively, withdip-coating, all substrate sides can be coated. Precursor compositioncan vary, without limitation, in terms of Al/P stoichiometry, viscosity,carrier (e.g., aqueous or non-aqueous) and additives present (eitherorganic or inorganic). For example, as may be advantageous forhigh-emissivity coatings, a slurry can be prepared with a solvent(either aqueous or non-aqueous) carrier component.

With consideration of various volume and throughput requirements,coating compositions can be cured over lengths up to about 100 feet ormore, with one or more ovens or heating/curing sources. For instance, anoven or furnace of sufficient length to enable drying and curingaccording to a set schedule can be provide an effective temperatureranging from about 50C to 1,000C, with a residence time depending uponspeed and length of an effective heating/curing zone. Such a zone canvary with one or more heating or curing sources (e.g., UV/IR, flowingheated air, other or inert gas or resistive heating source). A cured,applied coating can be cleaned with an appropriate solvent, then driedbefore application of a subsequent coating. Alternatively, as can beemployed with composites comprising temperature-sensitive substrates(e.g., certain plastics) or with high throughput systems, curing can beaccomplished with a suitable heat source in such a way as to heat thecoating component at a relatively higher temperature, while keeping thesubstrate at a relatively lower temperature (e.g., at about 250 C orbelow), for a time sufficient (e.g., less than about 1 hour) for coatingcure without deleterious impact or effect on the substrate.

For various process-related considerations, it can be desirable to rollthe substrate at right angles prior to movement along or through aheating/curing source. If the substrate is reasonably wet or uncured,coating damage from bending will be minimal. Depending upon initialsurface roughness, a substrate can be electropolished or mechanicallypolished, as would be understood in the art, prior to cleaning andcoating application. Regardless, reference is made to schematic FIGS. 17and 18 for further illustration of roll to roll/continuous coatingprocesses, and a non-limiting wound or rolled composite configurationresulting therefrom.

1. A configured composite comprising a silicon carbide substrate and acoating thereon comprising an aluminum phosphate compound containingAl—O—Al bonds and having an aluminum to phosphorous ratio from about 0.5to 1 to about 25 to
 1. 2. A configured composite of claim 1 in which thecoated silicon carbide is planarized.
 3. A configured composite of claim2 suitable as an optical device.
 4. A configured composite of claim 1formed by coating a silicon carbide substrate with a precursor alcoholicsolution containing an aluminum salt and an phosphorus ester and dryingand curing the coating.
 5. A configured composite of claim 4 in whichthe aluminum salt is aluminum nitrate.
 6. A configured composite ofclaim 4 in which the alcoholic solution is formed in ethanol ormethanol.
 7. A configured composite of claim 4 in which the phosphorusester is formed from phosphorus pentoxide.